1. Technical Field
This invention relates to retractable overhead tool supports, and more particularly to a low-drag overhead support for lightweight hand-held tools such as hairdryers.
2. Background Information
In various industries, hand tools and other utilitarian devices are used by workers on a daily basis. Many of these devices are heavy, and require considerable arm strength to lift, hold in place, and maneuver. Weight compensating suspension devices may be desired to support relatively heavy objects from above, such as to support engine blocks and the like in automobile assembly lines. These devices enable the heavy objects to be conveniently moved to or along the production line, enabling workers to rotate them for convenient access, e.g., to attach components, or to lower them into position, such as into an engine compartment of an automobile. In order to support such heavy objects, these suspension devices may be fabricated from relatively heavy components to provide them with requisite structural integrity. These suspension devices, by virtue of their intended use and structural requirements, therefore tend to have relatively high inertial mass. Such devices also tend to exhibit relatively high frictional forces during use.
As mentioned above, the supported objects are themselves heavy and as such, are typically moved into desired position slowly, and once so positioned, e.g., at a desired elevation within an assembly line, or within an engine compartment of an automobile, are seldom moved elevationally again, if at all. Accordingly, for such applications, the mass, inertia, and friction of the suspension device is of little adverse affect.
However, such suspension devices are less than optimal for use with relatively lightweight objects, such as hairdryers and other hand tools, which have relatively low mass, and which are often moved rapidly between various elevations. For example, hair stylists use hand-held hair dryers, which often must be held for extended periods of time and maneuvered quickly and repetitively between various elevations, sometimes in tandem with a hairbrush while drying or styling.
Even when appropriately scaled down in size to compensate for the lighter weight of such objects, conventional suspension devices of the type described above have generally proven deficient in one or more respects. For example, such devices tend to either provide too much, or too little compensating (e.g., upward) force and the cords used to attach these devices to the supported object tend to bind during rapid elevational changes (i.e., during rapid raising and lowering). Furthermore, during such rapid elevational movement, such as during the hair styling/drying action described above, there may be a lag between raising the hairdryer, and the corresponding retraction of the cord. This lag may result in the cord becoming alternately loose, and then taut, to provide non-uniform tool support which may be disruptive to the user. Moreover, the momentary lag may result in a subsequent retraction at an excessive rate of speed, as the device attempts to reel in xe2x80x98slackxe2x80x99 in the cord. Alternatively, the device may attempt to retract the cord even as the user attempts to lower the object, which may be further disruptive, and may place undue stress on the user""s wrist and on various components of the suspension device, etc. This uneven application of force generated by such a lag may also result in components of the device disadvantageously cocking or jamming.
It is therefore desirable to provide an improved suspension apparatus for lightweight objects such as hairdryers and other hand tools, which renders them apparently or virtually weightless, while enabling them to be frequently and quickly moved between various elevations while also providing lateral freedom of movement.
In one aspect of the present invention, a multi-elevational hairdryer support includes a frame configured for mounting to a ceiling, and a drum rotatably coupled to the frame for rotation about a central axis, the drum having an exterior frusto-conical surface. A helical channel extends along the frusto-conical surface, a coiled spring is disposed to bias rotation of the drum, and a cord is coupled at a proximal end thereof to the drum. A hairdryer is coupled to a distal end of the cord, which is configured to supply electrical power to the hairdryer. The helical channel windingly receives the power cord therein, so that it may be alternately wound and unwound with and against the bias of the spring as the hairdryer is respectively raised and lowered. The drum is configured for moving axially during the alternate winding and unwinding. The cord alternately exits and enters the helical channel via an axially stable point during the alternate unwinding and winding. The spring is coupled to the drum at an axially stationary location which is orthogonally aligned with the entry and exit point relative to the axis. The spring is also configured for remaining axially stationary during the axial movement of the drum.
In another aspect of the invention, a low-drag counter-balance apparatus is provided for offsetting a constant force between two points of reference, over a range of movement, the points of reference respectively defining a point of attachment to the force and an axis of rotation. The apparatus includes a drum configured to rotate about the axis of rotation, and a spring operatively engaged with the drum to bias rotation of the drum, the drum having a surface defining a helical path thereon. A cord is coupled at a proximal end thereof to the drum, the cord being coupled at a distal end thereof to the force. The cord is configured to be alternately wound and unwound about the drum along the helical path during the rotation of the drum, respectively with and against the bias. An entry/exit location is provided, where the cord alternately engages and disengages the drum during the winding and unwinding; and the entry/exit point and the spring are configured for being axially stationary relative to one another during the winding and unwinding.
In a yet further aspect of the invention, a low-drag multi-elevational hairdryer support includes a frame configured for mounting to a ceiling, a shaft disposed on the frame, low-friction rolled threads disposed along a first portion of the shaft, a substantially smooth low-friction spring support disposed concentrically with an other portion of the shaft, the spring support having a lubricious outer surface configured to slidably support a spring concentrically disposed therewith. A drum is provided with an integral self-lubricating inner threaded bore, the threaded bore disposed in rotational engagement with the low-friction rolled threads, the drum also having an exterior frusto-conical surface. A helical path extends along the frusto-conical surface, and a coiled spring is disposed to bias rotation of the drum, the spring having a first number of coils concentrically superposed with the spring support, and disposed in axially spaced relation to one another, so that the coils are free from mutual engagement during rotation of the drum. The helical path extends for a second number of revolutions about the drum, so that the ratio of the first number of coils to the second number of revolutions is at least 11:1. A cord is coupled at a proximal end thereof to the drum, and a hairdryer is coupled to a distal end of the cord, the cord configured to supply electrical power to the hairdryer. The helical path is configured to windingly receive the cord thereon, the cord configured for being alternately wound and unwound with and against the bias of the spring as the hairdryer is respectively raised and lowered. The support has a drag force opposing elevational movement of the hairdryer of less than 0.5 pounds (0.2 kg).
Aspects of the invention also include a method for offsetting a constant force between two points of reference, over a range of movement, the points of reference respectively defining a point of attachment to the force and an axis of rotation. The method includes configuring a drum to rotate about the axis of rotation, operatively engaging a spring with the drum to bias rotation of the drum, providing a surface defining a helical path thereon, and coupling a proximal end of the cord to the drum. The method further includes configuring a distal end of the cord for coupling to the force, configuring the cord for being alternately wound and unwound about the drum along the helical path during the rotation of the drum, respectively with and against the bias, providing an entry/exit location where the cord alternately engages and disengages the drum during the winding and unwinding; and configuring the entry/exit point and the spring for being axially stationary relative to one another during the winding and unwinding.
In another aspect of the invention, a multi-elevational hairdryer support includes a drum disposed to rotate about a central axis. A coiled spring is disposed to bias rotation of the drum, and a cord is coupled at a proximal end thereof to the drum. A hairdryer is coupled to a distal end of the cord, which is configured to supply electrical power to the hairdryer. The drum windingly receives the power cord thereon, so that it may be alternately wound and unwound with and against the bias of the spring as the hairdryer is respectively raised and lowered. The drum is configured for moving axially during the alternate winding and unwinding. The cord alternately exits and enters the helical channel via an axially stable point during the alternate unwinding and winding. The spring is coupled to the drum at an axially stationary location which is orthogonally aligned with the entry and exit point relative to the axis. The spring is also configured for remaining axially stationary during the axial movement of the drum.
In a still further aspect, an adjustable apparatus is provided for offsetting the weight of a hairdryer and cord over a range of movement. The apparatus includes a drum configured to rotate about an axis of rotation, a spring operatively engaged with the drum to bias rotation of the drum, and a cord coupled at a proximal end thereof to the drum, the cord coupled at a distal end thereof to the hairdryer. The cord is configured to be alternately wound and unwound about the drum, respectively with and against the bias. A tension adjuster is coupled to the spring, and is configured to adjust the bias over a range of from 0-100% of the weight of the hairdryer and cord.